How to learn Cert skills?

As mentioned before, each cert has 8 professional skills. However, these skills are not learned by your character immediately. They are separated by four tiers or levels, with two new skills unlocked as you go up your Cert's tier. Like other mastery skills, you still have to reach certain mastery level, before you unlock the skill. Once the skill is available/unlocked, you still need to spend new dollars and skill points to learn them.

In the example below, I started as a Rifleman I so I'll only have access to the skills Quick Dissection. To learn Break the Surface, the second skill of the same tier, I still have to reach Combat Mastery LV15 and shell out the indicated amount of new dollars and skill points.To access the next set of skills (Destructive Madman and Honor Badge), I have to get Promoted first. (Follow the link for more details)\